title: Patterns of left ventricular contraction in strain vector space related to bundle branch block with heart failure by speckle-tracking echocardiography.
abstract: The aim of this research is to study bundle branch block (BBB)-related patterns of radial strain in the left ventricles of patients with heart failure by speckle-tracking echocardiography. Twenty-seven left-BBB (LBBB), 10 right-BBB (RBBB), and 11 narrow QRS-complexes (non-BBB) patients and 11 healthy subjects were assessed. Strain fractions used to quantify thickening-during-systole and thinning-during-diastole, and timing parameters defined as time to onset-of-thickening and peak-strain were measured. Principal strain vectors were conducted on the fractions and parameters to analyze mechanical discoordination and dyssynchrony. Heart failure patients show a significantly greater extent of discoordination and dyssynchrony compared with healthy subjects. Significant differences between the LBBB and RBBB groups are demonstrated by deflection, a spatial characteristic of myocardial coordination. New information provided by these findings can provide a better understanding of BBB-related mechanisms of myocardial coordination and may be useful in improving patient selection, electrode placement and subsequent outcomes for cardiac resynchronization therapy.
authors.affiliation: Department of Electrical Engineering, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Pei-Kuang
authors.initials: PK
authors.lastname: Chao
authors.forename: Hsiao-Lung
authors.initials: HL
authors.lastname: Chan
authors.forename: Chun-Li
authors.initials: CL
authors.lastname: Wang
authors.forename: Lung-Sheng
authors.initials: LS
authors.lastname: Wu
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004452:Echocardiography / Q000379:methods; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*